1. Field of the Invention
The present invention relates to an optometry apparatus for examining or measuring an examinee's eye.
2. Description of Related Art
As a target projecting optical system of an optometry apparatus such as an eye refractive power measurement apparatus, an optometer, and an eye accommodation measurement apparatus, an optical system having diopter movement means and astigmatism correction means has been known (e.g., Jpn. unexamined patent publication No. 11-70076(1999)). The diopter movement means is adapted to perform diopter movement by for example moving a target in a direction of a projection optical axis of the target projecting optical system or moving a lens in the direction of the projection optical axis. For a downsized apparatus, it is preferred that a moving amount (range) of the diopter movement means such as the target and the lens is as small as possible. On the other hand, the astigmatism correction means is adapted to perform astigmatism correction by for example rotating two cross-cylinder lenses about the projection optical axis respectively. To clearly present the target to the examinee's eye, it is preferred that the target is less affected by aberration of the astigmatism correction means such as the cross-cylinder lenses.